Leesoft Postman is able to send emails to a large number of recipients in high speed. It acts as a SMTP relay sending emails directly to recipients without any other SMTP servers. It will show the response after sending an email immediately. Users can know if their email marketing campaign was successful or not without guessing or waiting. The program is a mutilpile threads software. Users is able to define the number of threads the sending email process will launch. With this technology, it sends emails in very high speed. Users can load recipients information such as email address and name from databases or text files. The program supports customize SQL to load recipients information while loading them from databases. It has some tags to help users to place recipients information in emails to build personalize emails. It is able to send emails in HTML or text format.